The present invention relates to a process for repairing vinyl base material such as automotive upholstery and vinyl tops.
Vinyl materials have become extremely popular for use in automobiles, home furnishings and the like. The surface of vinyl materials can be textured to simulate almost any pattern desired. An example of this is simulated leather upholstery.
Vinyl materials can be damaged by cigarette burns, knife cuts, tears, splits and the like.
U.S. Pat. No. 3,620,865 describes a process for repairing flexible vinyl materials by applying thin layers of a clear liquid vinyl-welding compound to the hole in a damaged vinyl base material. Each layer is cured in the hole and fused to the adjacent vinyl base material by application of heat. The top layer and the adjacent surface of the vinyl base material are grained by heating the area to soften it, applying a graining tool having the grain pattern of the damaged base material on the die face to the softened area, maintaining the graining tool on the softened area under a slight pressure, and then cooling the grained area while maintaining a slight pressure to allow the grained softened area to harden. The graining tool is made from an opaque graining compound containing polyester resin, calcium carbonate, and talc. This opaque material is poured onto vinyl having the grain or surface texture of the piece being repaired and allowed to set up. Color is applied to the repaired area with a vinyl color spray so that it will match the vinyl base material.
Although this process has proven to be successful, it is not without disadvantages. Among the disadvantages is that the vinyl color spray easily wears off the surface of the repair, thereby leaving the non-pigmented welding compound material visible. Attempts to overcome this problem by pigmenting the welding repair material to match the vinyl base material have generally been unsatisfactory because when the vinyl repair material matches the vinyl base material, it is very difficult to ascertain whether the repair material has fused into the vinyl base material. Therefore, inadequate fusion often occurs resulting in a very weak repair.
Another disadvantage with this process is that the graining tool is opaque and it is very difficult to index the die surface of the graining tool with the grain pattern of the vinyl base material so that the grain in the repaired area blends in and matches the grain of the base material. Furthermore, the polyester resin used for the graining tool degrades at the temperature at which the vinyl base material and the vinyl-welding compound soften. Thus it is necessary to preheat the repair before applying the graining tool which is a time consuming procedure. A quicker repair occurs with heat applied directly through the graining tool to the repaired area.